textproduct: Rapid City

KEY MESSAGES

- Pattern change today as cold front settles in later tonight. Cooler with precipitation chances through the week.

UPDATE

Issued at 952 PM MDT Sat Oct 10 2026

00z sfc analysis depicts sfc trof across western SD into northeastern WY. Showers and isolated storms have develop over northwestern SD and portions of northeastern WY. Cooler air to the northwest will push into the area overnight with highs tomorrow in the mid 50s across NW SD to the 70s across south central SD. Cooler, more seasonable temps expected through next week. Precip chances will be slim for much of the week until the Wednesday/Thursday timeframe, though there still isn't much consensus among deterministic and ensemble guidance.

DISCUSSION

(This Evening Through Saturday) Issued at 1236 PM MDT Sat Oct 10 2026

Upper level analysis shows broad southwesterly flow across the Northern Rockies into the Northern Plains. Deep troughing is noted across the western US with closed upper low dropping into WA with a second closed low off the southern CA coast. Surface low pressure is centered over central ND with a cold front extending westward through southeastern MT, slowly pushing into far northwestern SD. Surface winds in northwestern SD have shifted out of the northwest, with west-southwesterly winds across the rest of the CWA. Very hot today with widespread 80s and to low 90s, warmest across the western SD plains.

Isolated showers and a few lightning strikes are possible later this afternoon and evening hours as shortwave trough pushes into the region. Given dry boundary layer, lack of appreciable moisture, and isolated coverage, precipitation amounts will be light and spotty. However, gusty winds are possible with any precipitation cores. The cold front will settle southward into the forecast area tonight. Cooler temperatures behind the front, although frontal position a bit uncertain Sunday. Current thinking is that the front will be slow to push south of the area, allowing for warmer temperatures along SD/NE border (70s) and cooler temperatures northward through Sunday afternoon.

Cold front will shift south of the area by Monday with cooler, yet near seasonable temperatures through the rest of the week. Active southwesterly flow aloft coupled with moisture influx from the remnants of Tropical Storm Rachel will support precipitation chances late Sunday into Monday, although best precipitation chances will be displaced north and northwest of the forecast area. A deep upper low is forecast to push through the area late Tuesday into Wednesday with another chance of precipitation Wednesday.

Forecast confidence wanes beyond Wednesday with considerable spread among the models/ensembles regarding the synoptic evolution.

AVIATION

(For the 12Z TAFS Through 12Z Monday Morning) Issued At 459 AM MDT Sun Oct 11 2026

Expect MVFR to local IFR cigs across the far northwest this morning, trending to MVFR late this morning. Sct showers will also be possible across the northwest third. Otherwise, winds will veer around to the ESE through the period ahead of the next wave. A batch of showers will move through this evening, with local MVFR conds possible in the heavier showers. Easterly upslope flow will support patchy fog and MVFR to local IFR cigs on the NW SD Plains and along the eastern BH foothills tonight.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.